This invention relates to aircraft de-icing and, more particularly, to a system and method of onboard de-icing.
Ice formation on aircraft surfaces, particularly wing surfaces, during cold weather is a problem that can have catastrophic consequences. Ice increases aircraft weight and can reduce lift and interfere with the functioning of moving parts. A number of systems are available and in use for preventing icing or for de-icing an aircraft surface while an aircraft is in flight. These include de-icing devices which remove ice by scraping or cracking, devices which melt the ice with microwave heating and devices which employ electrothermal heating within the structure to be de-iced. These devices are typically slow and inefficient. They must also typically be positioned in or adjacent the area to be de-iced and lack the flexibility to de-ice different surfaces and moving parts of the airfoil.
It has also been proposed to use ground based laser light systems to de-ice aircraft. Such systems typically use complex, bulky and cumbersome booms to hold laser light generators in close proximity to an aircraft surface and to manipulate the laser light generators about the aircraft surface to be de-iced. In U.S. patent application Ser. No. 08/706,598, filed by the present inventor, a laser de-icing method and system are disclosed which overcome many of the problems of earlier laser de-icing systems. The entire content of U.S. patent application Ser. No. 08/706,598 is incorporated by reference herein as if set forth fully herein. While laser de-icing offers a relatively fast and efficient way of removing ice from an aircraft and reduces or eliminates the need to spray outer surfaces with glycol solutions for de-icing on the ground, earlier approaches of others to laser de-icing are not without problems. For example, ground based systems proposed by others do not permit in flight de-icing and significantly limit the flexibility of the system to de-ice the aircraft when and where needed. Furthermore, glycol based de-icing systems must use additional glycol mixtures and compounds to enable the aircraft to travel from the de-icing station to the runway and to preserve the ice free condition during take-off. The anti-icing glycol mixtures and compounds provide several minutes of ice free conditions. If the aircraft exceeds the specified "safe" period, the aircraft must return to the de-icing station.